First Author | Dichek HL | Year | 2001 |
Journal | J Lipid Res | Volume | 42 |
Issue | 2 | Pages | 201-10 |
PubMed ID | 11181749 | Mgi Jnum | J:68351 |
Mgi Id | MGI:1932596 | Citation | Dichek HL, et al. (2001) Hepatic lipase overexpression lowers remnant and LDL levels by a noncatalytic mechanism in LDL receptor-deficient mice. J Lipid Res 42(2):201-10 |
abstractText | To address the role of the noncatalytic ligand function of hepatic lipase (HL) in low density lipoprotein (LDL) receptor-mediated lipoprotein metabolism, we characterized transgenic mice lacking the LDL receptor (LDLR) that express either catalytically active (Ldlr(-/-)HL) or inactive (Ldlr(-/-)HL(S145G)) human HL on both chow and high fat diets and compared them with nontransgenic Ldlr(-/-) mice. In mice fed a chow diet, apolipoprotein (apo)B-containing lipoprotein levels were 40-60% lower in Ldlr(-/-)HL and Ldlr(-/-)HL(S145G) mice than in Ldlr(-/-) mice. This decrease was mainly reflected by decreased apoB-48 levels in the Ldlr(-/-)HL mice and by decreased apoB-100 levels in Ldlr(-/-) HL(S145G) mice. These findings indicate that HL can reduce apoB-100-containing lipoproteins through a noncatalytic ligand activity that is independent of the LDLR. Cholesterol enrichment of the apoB-containing lipoproteins induced by feeding Ldlr(-/-)HL and Ldlr(-/-)HL(S145G) mice a cholesterol-enriched high fat (Western) diet resulted in parallel decreases in both apoB-100 and apoB-48 levels, indicating that HL is particularly efficient at reducing cholesterol-enriched apoB-containing lipoproteins through both catalytic and noncatalytic mechanisms. These data suggest that the noncatalytic function of HL provides an alternate clearance pathway for apoB-100- and apoB-48-containing lipoproteins that is independent of the LDLR and that contributes to the clearance of high density lipoproteins. |